Image-recording devices known in the art record images by depositing recording material on recording paper. Often the recording material is supplied in the form of cartridges. In recent years, manufacturers of such cartridges have provided a service for delivering cartridges containing the recording material to the users of the image-recording devices. While such services are provided for image-recording devices, a personal computer or other information processor can be used to enter new service agreements, cancel agreements, and the like. A communication system configured of client terminals such as image-recording devices, and an administrative server connected to the client terminals over a network is known.